Anti-sway bar assembly

ABSTRACT

A modular anti-sway bar assembly for heavy duty vehicles. The anti-sway bar has multiple components including a main torsion bar which is equipped at each end with a splined connecting surface. The splined ends of the main torsion bar allow it to be easily disconnected and removed from the vehicle. Each of the splined ends of the main torsion bar is gripped by an arm, which is generally horizontally oriented and which is connected by a vertical link to a wheel end. The main torsion bar is guided along its length and restrained from axial motion by a pair of support bushings, each of which is held in a pocket in a suspension side plate. The main torsion bar passes through openings in the side plates.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to large vehicles having independentsuspensions, such as those which are typically used in militaryapplications and in large municipal vehicles, such as fire trucks. Inparticular, the invention relates to a frame and independent suspensionassembly which allows a vehicle to have better stability by lowering thecenter of gravity, better visibility because of the lower drivetain andlower hoodline, and greater ease of repair.

Military and other emergency vehicles must be designed to extremelydemanding specifications. The vehicles must be capable of driving overor through obstacles that only a tactical or emergency operator wouldattempt. The vehicles must be able to endure corrosive, partiallysubmerged and frequently dirty environments, such as standing water,chemicals or deep mud.

In addition, it is desirable for such vehicles to provide maximumforward visibility for the operator and maximum load carrying capacity.One step which has been taken in the design of heavy duty vehicles hasbeen to utilize C-shaped channels as the main frame members. The use oftwo widely-spaced beams provides a space where of various engine,transmission and other essential components can be mounted. Making morespace available along the center line of the vehicle frame allows heavycomponents to be more effectively mounted at a lower elevation which, inturn, lowers the vehicle's center of gravity. Vehicles with low centersof gravity have improved stability. A lower center of gravity in avehicle provides improved resistance to overturning as the vehicletraverses rough terrain or maneuvers around obstacles at high rates ofspeed. The improved visibility that results from a lowering of avehicle's drive train and hoodline allows for safer operation of thevehicle. The rough treatment to which military vehicles are exposed issevere. These vehicles are required to cary very heavy cargo over veryrough terraine. In case of trouble, these vehicles need to be readilyrepairable so that they do not become stranded. While the presentinvention has particular application in the context of frame memberswhich are C-shaped, the invention may be used with frame members havingother shapes, such at tubular shapes (rounded and rectangular) and otherstructurally advantageous shapes.

The present invention provides a vehicle with a lower center of gravity,both with respect to vehicle components and with respect to cargo areas.These and other advantages are accomplished by using weldments whichattach to and reach under the main frame members. The weldments includeopposing side plates. Each side plate has two buttress-type end plateswhich support a main side plate member. The main side plate members arecomprised of four generally rectilinerally oriented and integrallyformed plates. Small buttress plates are used to define pockets forsuspension components such as a suspension spring and shock absorber.The weldments may include a pocket for a sway bar bushing and an openingwhich allows a sway bar to pass through the pair of weldments. Anon-contact spring guide may be mounted inside a suspension coil spring.The spring and spring guide are mounted between a lower control arm anda bearing plate carried by the front weldment of the present invention.The spring guide cooperates with a spring guide bushing, which is alsocarried by the bearing plate and which extends into the interior of thecoil spring.

Each of the weldments of the present invention incorporates a bushingsupport which guides the passage of a modular sway bar through theweldment. The sway bar is comprised of a straight main torsion bar withsplined ends. The splined ends are releasably gripped by arms on eachside of the vehicle. The arms are connected to the wheel ends byvertical links. If the torsion bar or an arm or a link should becomeoverstressed or damaged, any one of these components may be easilyreplaced, unlike prior U-shaped sway bars of unitary construction.

Other features and advantages of the present invention will be betterunderstood upon a reading of the following specification, read togetherwith the accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a pair of front weldments and portionsof a front axle constructed in accordance with the present invention;

FIG. 2 is a second perspective view of the weldments shown in FIG. 1with other suspension components shown adjacent thereto;

FIG. 3 is a third perspective view of the weldments shown in FIGS. 1 and2;

FIG. 4 is a side-elevational view of a front left-hand weldment of thepresent invention, as configured with no anti-sway bar;

FIG. 5 is an end view of the weldment shown in FIG. 4;

FIG. 6 is a top plan view of the weldment shown in FIGS. 4 and 5;

FIG. 7 is side-elevational view of a rear left-hand weldment of thepresent invention, as configured for use with an anti-sway bar;

FIG. 8 is an end view of the weldment shown in FIG. 7;

FIG. 9 is a top plan view of the weldment shown in FIGS. 7 and 8;

FIG. 10 is an exploded perspective view of a lower control armconstructed in accordance with the present invention;

FIG. 11 is cross-sectional view of a bushing assembly of the control armof the present invention;

FIG. 12 is an exploded perspective view of an anti-sway bar assemblymade in accordance with the present invention;

FIG. 13 is an end view of the spring guide bushing shown in FIG. 14 madein accordance with the present invention;

FIG. 14 is a cross-sectional view showing a bushing for a spring guide;and

FIG. 15 is a longitudinal cross-section through a spring guide made inaccordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 shows the front portion of a vehicle and its suspension supportin relation to a frame rail 2 of a vehicle. A left-hand or first sideplate 10 is mounted beneath a left-hand frame rail (not shown), and aright-hand or second side plate 12 is mounted beneath a right-hand framerail 2. Several bolts are used to connect each of the side plates 10 and12 to its respective frame rail. A differential 15 with a differentialdrive connection 14 is connected to each of the side plates 10 and 12.As further shown in FIGS. 2 and 3, it is clear that the side plates 10and 12 are rigidly joined together by the lower plate 20, bar 22 anddifferential 15 at the lower portions of the side plates 10 and 12. Theside plates shown in FIGS. 1 through 6 are for a suspension that is notequipped with an anti-sway bar.

Referring now to the first plate 10 shown in FIGS. 1 through 6, it iscomprised of three main components which are welded together. Thosecomponents are: a longitudinally extending main plate memeber 51; aleading end plate 48; and a trailing end plate 50. Longitudinallyextending plate member 51 includes four sections; an upper verticalplate section 52; a horizontal plate section 54; a lower vertical platesection 56; and a lower lip 58. The upper vertical plate section 52 andthe lower vertical plate section 56 are in a off-set and generallyparallel relationship. Extending from the outer face of the uppervertical plate section 52 are three pockets including a shock absorberpocket 38 formed by gusset plates 40 and a bearing plate 42, a jouncebumper pocket 61 formed by gusset plates 40 and 46 and jounce bumperplate 62, and a coil spring pocket 39, defined by the end plate 48,gusset plate 46 and coil spring bearing plate 47. A lifting lug 44 maybe welded to the bearing plate 47 for use in lifting the completevehicle. The lower vertical plate section 56 has an opening 70 so that ahalf-shaft 16 can extend from the differential 15 to the wheel end 18(see FIG. 1).

As is most clearly shown in FIG. 2, the elements of the suspensionsystem are connected to the outer portions of the first side plate 10.The shock absorber 24 extends from the bearing plate 42 to the lowercontrol arm 32. Similarly, the suspension coil spring 26 extends fromthe lower control arm 32 to the bearing plate 47. In addition, insidethe suspension coil spring 26, a spring guide 28 extends from the lowercontrol arm 32 into the spring guide bushing 30 which is bolted to thecoil spring bearing plate 47. An upper control arm 34 is connected by aball joint 37 to an upper portion of the steering knuckle 41. The upperand lower control arms 34 and 32, respectively, are held in place byfour control arm mounting assemblies 94, an example of which is moreclearly shown in FIG. 10 discussed below. The locations of the controlarm mounting assemblies for a left-hand side plate 10 can best be seenin FIG. 4 wherein upper control arm attachment locations 68 and lowercontrol arm attachment locations 66 are at upper and lower portions ofthe vertical mounting plate 56. An ear 78 is used to support varioussystem lines, i.e., hoses and wires, etc., which lead to the wheel end18. A stiffening flange 60 extends from the outer edge of the end plate50 to provide the plate 50 with increased resistance to buckling.

FIGS. 7, 8 and 9 show a left-hand side plate 10 a for use with ananti-sway bar. In describing the anti-sway bar equipped left-hand sideplate 10 a, the same reference numerals used to indicate portions of thenon anti-sway bar side plate 10 are used for components which are thesame. For example, a coil spring bearing plate 47 extends between an endplate 48 and a gusset 46 to define a pocket 38 for a coil spring (notshown in FIG. 7). The left-hand side plate 10 a includes upper controlarm mounting locations 68 and lower control arm mounting locations 66.Gusset plates 40 and shock absorber bearing plate 42 define a shockabsorber pocket 38. However, an element which is part of the left-handside plate 10 a, which is not included in the side plate 10 is a bushingpocket 76 and an opening 74 (as shown in FIG. 7) through which extendsan anti-sway bar 112, more details of which are shown in FIG. 12. FIGS.6 and 9 further illustrate an opening 72 that allows for the coil springand spring guide movement.

FIG. 10 is an exploded view of a lower control arm assembly. The lowercontrol arm 32 has two control arm mounting assemblies 94, one of whichis shown in exploded form on the left side of FIG. 10. The control armmounting assembly 94 includes a pin 96 and two bushing assemblies 98(more detail of which is shown in FIG. 11). The ends of the pin 96 areclamped by the blocks 36 as the blocks 36 are attached to the lowervertical plate section 56 of a side plate. A thrust washer 108 isdisposed between each bushing assembly 98 and a block 36. A screw 110and washer 111 are used to properly pre-load the bushing assembly 98before installation. The lower control arm 32 includes a spring mount 90through which there extends a spring pivot pin 91 and a sleeve bearing95. A spring seat 84 with a threaded hole 85 for receiving the springguide 28 (See FIGS. 2 and 15 for further detail of spring guide 28)straddles the spring mount 90. A small dowel pin 89 retains the pin inthe spring seat 84 and causes the spring seat 84 to rotate the springpivot pin 91 within the sleeve bearing 95. A pair of seals 93 preventcontaminants from entering the sleeve bearing 95 within the spring mount90. FIG. 10 also shows a ball joint assembly, within which is housed asocket 80 on the outer end of the lower control arm 32.

FIG. 11 is an enlarged cross-sectional view of the bushing assembly 98which is part of the control arm mounting assembly 94. The bushingassembly 98 includes an inner sleeve bearing 106, an intermediate metalsleeve 104 and an outer elastomeric sleeve 102 which has a flange 107 atone end and annualar ribs and grooves on the outside surface thereof. Aseal 100 engages a shoulder formed on the outer edge of the intermediatesleeve 104. The bushing assembly 98 fits snugly into a bore formed atthe inside end of each leg of the lower control arm 32. As the block 36is tightened into position against the lower vertical plate section 56of an end plate, the pin 96 is gripped by the block 36 as a result ofthe closing of the gap formed by the slot 97 in the block 36. A slot ineach block 36 of a control arm mounting assembly allows for easy removalof a pin 96 from the assembly 94. Arranging the slots 97 so that theyface down makes it harder for water and mud to flow into the pin/blockjoint.

FIG. 12 shows the anti-sway assembly which forms a part of the presentinvention. An anti-sway bar 112 has a splined end 114 and extendsthrough the opening 74 in the upper vertical plate section 52 of a sideplate 10 a. The anti-sway bar 112 is supported by a bushing 116. Thebushing 116 is contained in a pocket 73, the top portion of which isformed by a removable plate 124. One end of the plate 124 is insertedinto a slot 77 formed in a gusset plate 40, and the other end of plate124 is held in place by bolts. A pair of collars 118 maintain theposition of the anti-sway bar 112 in the bushing 116. A pair of seals119 prevent contaminants from entering the bushing 116. The splined end114 of the anti-sway bar 112 is engaged in and clamped by an end of thearm 120. A vertical link 122 connects an end of the arm 120 to thesteering knuckle 41, as shown in FIG. 3.

FIGS. 13 and 14 show the spring guide bushing 30 which is attached tothe coil spring bearing plate 47 on the front side plates 10 and 12. Thespring guide bushing 30 includes a tapered bore through which a springguide 28 extends. The taper allows the spring guide 28 to articulateslightly within the bushing 30. Three mounting ears 33 facilitate theconnection of the bushing 30 to the bearing plate 47. The bushing 30 ismounted in the orientation shown in FIG. 2 so that the narrower end ofthe tapered opening 31 is upward, i.e., the bushing 30 extends down intoand through the opening in the bearing plate 47. The rear spring isstable enough by itself not to need a guide. The spring guide 28 isshown in FIG. 15. The spring guide 28 has a threaded end 27 whichthreads into the threaded hole 85 in the spring seat 84. (See FIG. 10.)A stop 35 is welded to the body of the spring guide 28 to limit thethreaded engagement of the threaded end 27 and the spring seat 84. Atthe opposite end of the spring guide 28, a drive socket 29 isincorporated to facilitate the threaded engagement of the spring guide28 into the spring seat 84 with a common wrench. It should be noted thatthe diameter of the spring guide 28 is substantially smaller than theinside diameter of the coil spring 26 through which it extends. Theresult is a non-contact spring guide. The spring guide 28 is free toslide within the tapered opening 31 in the spring guide bushing 30 asthe wheel of a vehicle moves up and down. The alignment of the springseat 84, however, is maintained so that buckling of the coil spring 26is prevented, even in instances where there is a large compression ofthe spring as a result of relative movement of the wheel and the frame.

Having described a number of features, discoveries and principalsembodied in the foregoing examples, it is intended and will beunderstood by those skilled in the art, that a number of modifications,alternatives and variations thereof may be made while stillincorporating the spirit and scope of the invention as claimed below.

What is claimed is:
 1. An anti-sway bar assembly comprising a maintorsion bar having splines on at least one end, and arm with matingsection in gripping engagement with said splined end, said arm has aninternally splined clamp, said clamp making a rigid non-rotativeconnection with said splined end of said main torsion bar, said armbeing removeably attached and extending generally perpendicular to saidmain torsion bar, and a link for connecting to an upwardly anddownwardly to a portion of a wheel end; said assembly includes a bushingthrough which said main torsion bar extends, said bushing being shapedto fit in a pocket in an outside face of a vehicle suspension systemside plate; said assembly further includes a removable plate to holdsaid bushing in said pocket; said bushing has end flanges defining arecess on an exterior of said bushing; and said plate fitting into saidrecess and preventing axial movement of said bushing relative to saidpocket along an axis of said main torsion bar.
 2. An anti-sway bar inaccordance with claim 1 wherein: said main torsion bar adapted to extendthrough left and right rear side plates of a vehicle frame, and saidmain torsion bar being moveable axially into and out of an operatingposition for repair and replacement thereof, upon disconnection of saidsplined ends from their respective arms.
 3. An anti-sway bar assemblycomprising a main torsion bar having splines on at least one end, andarm with mating section in gripping engagement with said splined end,said arm has an internally splined clamp, said clamp making a rigidnon-rotative connection with said splined end of said main torsion bar,said arm being removeably attached and extending generally perpendicularto said main torsion bar, and a link for connecting to an upwardly anddownwardly to a portion of a wheel end; said assembly includes a bushingthrough which said main torsion bar extends, said bushing being shapedto fit in a pocket in an outside face of a vehicle suspension systemside plate; said assembly further includes a removable plate to holdsaid bushing in said pocket; and a collar on each side of said bushingholds said main torsion bar in a generally fixed position relative tosaid bushing.